Ios – Why some iphone apps won’t finish ssl handshake with Charles Proxy

To remotely capture http or https traffic with charles you will need to do the following:

HOST - Machine running Charles and hosting the proxy CLIENT – User’s machine generating the traffic you will capture

Host Machine

1. Install fully licensed charles version
2. Proxy -> Proxy Settings -> check “Enable Transparent HTTP Proxying”
3. Proxy -> SSL Proxying Settings -> check “enable SSL Proxying”
4. Proxy -> SSL Proxying Settings -> click Add button and input * in both fields
5. Proxy -> Access Control Settings -> Add your local subnet (ex: 192.168.2.0/24) to authorize all machines on your local network to use the proxy from another machine
6. It might be advisable to set up the “auto save tool” in charles, this will auto save and rotate the charles logs.

Client Machine:

1. Install and permanently accept/trust the charles SSL certificate
   http://www.charlesproxy.com/documentation/using-charles/ssl-certificates/
2. Configure IE, Firefox, and Chrome to use the socket charles is hosting the proxy on (ex: 192.168.1.100:8888)

When I tested this out I picked up two lines of a Facebook HTTPS chat (one was a line TO someone, and the other FROM)

you can also capture android emulator traffic this way if you start the emulator with:

emulator -avd <avd name> -http-proxy http://local_ip:8888/

Where LOCAL_IP is the IP address of your computer, not 127.0.0.1 as that is the IP address of the emulated phone.

Source: http://brakertech.com/capture-https-traffic-remotely-with-charles/

From iOS 10.3 you also need to go to Settings > General > About > Certificate Trust Settings and trust Charles certificate.